Nonwoven fabric comprising rosebuds connected by bundles

ABSTRACT

A nonwoven fabric having a plurality of patterns of groups of fiber segments that alternate and extend throughout the fabric. One of the patterns, disposed in discontinuous portions of the fabric, consists of fiber segments which are interentangled and in helter-skelter arrangement and protrude out of the plane of the fabric. These discontinuous portions of the fabric are interconnected by a plurality of yarn-like bundles of fiber segments which define apertures or holes or other areas of low fiber density in continuous portions of the fabric to form a second pattern.

F. KALWAITES Aug. 1, 1972 I NONWOVEN FABRIC COMPRISING ROSEBUDS CONNECTED BY BUNDLES Filed Mn 24, 1970 3 Sheets-Sheet 1 5 ma mm W4 mm M H F ATTORNEY g3 22 22a 23a F'. KALWAITES Aug. 1, 1972 NONWOVEN FABRIC COMPRISING ROSEBUDS CONNECTED BY BUNDLES Filed March 24, 1970 3 Sheets-Sheet 2 INVENTOR. K44 4 r55 g- 1972 F. KALWAITES NONWOVEN FABRIC comrmsmc ROSEBUDS CONNECTED BY BUNDLES Filed March 24, 1970 3 Sheets-Sheet 5 INVENTQR F/PAN/K 1444/ 7756 I\TTOR NEY United States Patent Office Patented Aug. 1, 1972 3,681,183 NONWOVEN FABRIC COMPRISING ROSEBUDS CONNECTED BY BUNDLES Frank Kalwaites, Somerville, N.J., assignor to Johnson & Johnson Filed Mar. 24, 1970, Ser. No. 22,292 Int. Cl. D0411 1/46, N70

US. Cl. 161-109 7 Claims ABSTRACT OF THE DISCLOSURE A nonwoven fabric having a plurality of patterns of groups of fiber segments that alternate and extend throughout the fabric. One of the patterns, disposed indiscontinuous portions of the fabric, consists of fiber segments which are interentangled and in helter-skelter arrangement and protrude out of the plane of the fabric.

These discontinuous portions of the fabric are interconnected by a plurality of yarn-like bundles of fiber segments which define apertures or holes or other areas of low fiber density in continuous portions of the fabric to form a second pattern.

BACKGROUND OF INVENTION For a number of years now, there have been known various types of forarninous or apertured nonwoven fabrics made by processes involving rearrangement of fibers in a starting web or layer of nonwoven fibers. Some of these fabrics and methods of manufacture are illustrated, shown and described in US. Patents 2,862,251; 3,081,500, and 3,081,515. The fabrics disclosed and claimed in the patents just listed contain apertures or holes or other areas of low fiber density, outlined by interconnected bundles of fibrous elements, wherein the fiber segments within the bundle are closely associated and substantially parallel, and have a yarn-like configuration. The term areas of low fiber density is used in this specification and claims to include both areas in which relatively few fibers in comparison to the rest of the fabric are found and apertures (holes) that are substantially or en tirely free of fibers. Such fabrics are sometimes referred to as bundled rearranged nonwoven fabrics.

Another type of rearranged fabric is shown, illustrated ,and described in US. Patent 3,033,721. In that fabric there are pivotal packings of fibers out of the plane of the fabric which are connected by flat, ribbon-like groups of fiber segments. These are generally termed and will be hereinafter referred to as rosebud nonwoven fabrics.

Bundled rearranged nonwoven fabrics have been made commercially for many years. In most instances, these fabrics have had an overall pattern of holes or other low fiber density areas throughout the fabric.

A method for producing bundled rearranged nonwoven fabrics is to support a loose fibrous web or layer on a permeable backing member and apply sets of opposed fluid forces to the layer while thus supported. The fluid by which such forces are applied passes through the fibrous layer, over the backing member, and then through the backing member, to pack various groups of the fiber elements and place these elements into close proximity and substantial parallelism to form interconnected bundles of fiber segments. In accomplishing this result, the fluid forces usually are applied over the entire surface of the loose fibrous web or layer and uniformly over and through a permeable backing or support member to produce fiber bundles uniformly over the entire fabric. In some instances, patterns can be made in the fabric by not applying fluid forces to predetermined areas of the fibrous layer, thereby preventing rearrangement in these areas.

A method for producing rosebud fabrics is quite similar; however the permeable backing member generally has larger apertures and the fluid is applied over the entire fibrous web while supported on the backing member. In some embodiments, a vacuum is placed behind the apertured backing member to aid in drawing the fluid through the Web and out through the apertures to pack the fiber elements into the apertures and form protuberant pivotal packings of fiber segments in the apertures of the backing member with the pivotal packings connected by flat, ribhon-like groups of fiber segments extending between the packings.

SUMMARY OF INVENTION I have discovered a novel nonwoven fabric which comprises a layer of intermingled fibers with the fibers arranged to define a plurality of patterns. The first pattern is of areas which are disposed in discontinuous portions of the fabric. These areas, consisting of fiber segments which are interentangled and in helter-skelter arrangement, protrude out of the 'plane of the fabric. The discontinuous areas are interconnected by a second pattern that comprises a plurality of yarn-like bundles of fiber segments located in continuous portions of the fabric lying between the discontinuous portions. The fiber segments in each of these bundles are closely associated with other fiber segments in the bundle and lie generally parallel to the longitudinal axis of the bundle. The yarn-like bundles define apertures or holes or other areas of low fiber density in the continuous portions of the fabric and form a second pattern in the fabric. The yarn-like bundles have an oval or circular cross-sectional configuration.

In some embodiments of the present invention, each discontinuous portion of the fabric has alternating areas of different fiber concentration across its area. By fiber concentration is meant the number of fiber segments per unit area in a given portion of the fabric, measured throughout the entire thickness of that portion.

Surprisingly, in my new fabric, even though it has a plurality of patterns which extend throughout the fabric, and the plurality of patterns involve difierent types of groups of fiber segments having considerable dilference in fiber configuration, the patterns have substantial regularity and aid in providing a fabric having considerable aesthetic appeal. Furthermore, not only does my new fabric have substantial uniformity in its various patterns of fiber segments, but my new fabric also has uniformity in the patterns of holes or apertures or other areas of low fiber density in the fabric.

METHOD OF MAKING THE FABRIC OF THIS INVENTION In manufacturing my new nonwoven fabric, the starting material is a layer of fibrous material whose individual fibers are in mechanical engagement with one another but are capable of movement under applied fluid forces. This starting material has a web weight of at least about 800 grains per square yard when the fibers of the material are 1 /2 denier, and somewhat heavier with higher denier fibers.

The layer of fibrous starting material is supported in a fiber rearranging zone in which fiber movement in directions parallel to the plane of said fibrous material is permitted in response to applied fluid forces. Streams of rearranging fluid, preferably water, are projected into the fibrous layer at entry zones spacedfrom each other adjacent one surface of the layer, each of the entry zones having a width at its narrowest part equal to at least about ten times, and preferably about twenty or more times the average diameter of the fibers of the fibrous starting material. These streams of rearranging fluid are passed through the layer of fibrous starting material as it lies in the rearranging zone, to effect movement of at least some segments of the fibers transverse to the direction of travel of the projected streams.

In thenext step of the method, the passage of first portions of the rearranging fluid out of the fibrous layer is blocked at continuous raised barrier zones located adjacentthe opposite surface of the fibrous layer, and, at the same time, those portions of fluid are deflected sidewise towards the other portions of the rearranging fluid andare actively mingled with the latter. Each of the raised barrier zones has a width at its narrowest part equal to from about one to about two times the width of one of the entry zones at its narrowest part. All the portions of intermingled rearranging fluid are then passed out of the rearranging zone through spaced, discontinuous apertures or formaminous fiber accumulating zones defined by the continuous raised barrier zones and each having an area at least about three times, and for improved results, at least about four or more times, the area of one of the entry zones.

The passage'of the rearranging fluid through the layer of fibrous starting material as just described moves some of the fiber segments that are in the registry with the continuous raised barrier zones into the fiber accumulating zones, and positions those fiber segments with other fiber segments in those zones in random, helter-skelter relationship with each other in mats of fibers. In addition, the rearranging fluid moves other fiber segments that are in registry with the continuous raised barrier zones into yarn-like bundles of closely associated and substantially parallel fiber segments extending between adjacent pairs of the discontinuous fiber accumulating zones.

The result of this fiber rearrangement is a nonwoven fabric having a first pattern of mats of randomly oriented fiber segments arranged in accordance with the pattern of the fiber accumulating zones. The mats are packed very tightly with highly entangled fiber segments. The fabric also includes a second pattern of yarn-like bundles of fiber segments extending between pairs of discontinuous portions of the fabric immediately adjacent each other in the first pattern.

An interesting embodiment of my novel nonwoven fabric is obtained when the foraminous portions of the backing means have a plurality of protuberances and troughs alternating across their surfaces in both the longitudinal and transverse directions. The discontinuous mats of randomly oriented fiber segments in the resulting fabric each have one surface embossed in accordance with the pattern complementary to the pattern of the protuberances and troughs of the foraminous portions of the backing means.

The basic method of this invention is shown and described full in my U.S. Pat. No. 2,862,251, issued Dec. 2, 1958. Full particulars of the basic invention as disclosed in that patent are incorporated in this application by reference, although some of those particulars are repeated here. In addition, the specific features peculiar to the method of the present invention are described in detail in this application.

Starting material.-The starting materialused with the method of this invention may be any of the standard fibrous webs'such as oriented card webs, isowebs, air-laid webs, or webs formed by liquid deposition. The webs may he formed in a single layer, or by laminating a plurality of the webs together. The fibers in the web may be arranged in a random manner or may be more or less oriented as in a card web. The individual fibers may be relatively straight or slightly bent. The fibers intersect at various angles to one another such that generally speaking, the adjacent fibers come into contact only at the points where they cross. The fibers are capable of movement under forces applied by fluids such as water, air, etc.

To produce afabric having the characteristic hand and drape of a textile fabric, the layer of starting material used with the method or apparatus of'this invention may comprise natural fibers such as cotton, flax, etc.; mineral fibers such as glass; artificial fibers such as viscose rayon, cellulose acetate, etc.; or synthetic fibers such as the polyamides, the polyesters, the acrylics, the polyolefin's, etc., alone or in combination with one another. The fibers used are those commonly considered textile fibers; that is, generally having a length from about inch to about 2 to 2 /2 inches.

Starting webs of about 800 grains per square yard to 2,000 grains per square yard or more may be used. With a starting material having a web weight of less than about 800 grains per square yard, mats of randomly oriented fiber segments may be formed, however, each of these mats will have associated with it, one or moreyarn-like bundles of fiber segments.

Apertured forming means.The apertured forming means used with the method of making the fabrics of this invention is solid throughout its area except for the forming apertures disposed longitudinally and transversely across the member. The forming apertures may have any desired shape, i.e., round, square, diamond, oblong, etc.

The width at the narrowest part of each of the apertures of the apertured forming means must be large enough that streams of rearranging fluid passing through those apertures will be effective to separate groups of fibers into yarn-like bundles spaced sufficiently far apart to permit reliable visual resolution. Without such resolution, any bundle of fiber segments produced would seem to the person viewing the fabric to fuse or merge together with other such bundles, with the result that no clear pattern would be aparent in the fabric. To achieve such resolution, the width of each aperture at its narrowest part should be equal to at least about ten times, and preferably at least about twenty times, the average diameter of the fibers in the fibrous starting material.

The maximum dimensions of each aperture of the apertured forming means are limited by the requirement mentioned below as to the ratio between the areas of the forming apertures and the foraminous portions of the backing means.

The land areas of the apertured forming means that lie between and interconnect the forming apertures may be either narrow or broad in comparison to the forming apertures as desired. Generally speaking, the narrower the land areas are, the more tightly compacted will be the yarn-like bundles of closely associated and substantially parallel fiber segments that are formed beneath those land areas.

Backing means having discontinuous foraminous portions.-As already indicated, the fibrous starting layer is supported on backing means having apertures or foraminous portions arranged in a discontinuous pattern, and continuous raised imperforate portions that lie be tween and interconnect the discontinuous foraminous portions to provide barrier zones against the passage of rearranging fluid out of the fiber rearranging zone.

The width of each imperforate portion of the backing means at its narrowest part is equal to from about one to about two times the width of the narrowest part of an aperture of the apertured forming means with which the backing means isused.

The area of each of the apertures or foraminous portions ofthe backing means is at least about three times the area of an aperture of the apertured forming means, in order to provide space for at least one yarn-like bundle on each side of the mat of randomly oriented fiber se ments that lies above each foraminous portion of the backing means.

In plan view, the discontinuous apertures or foraminous portions of the backing means may have any shape desired, i.e., circular, oval, diamond, square, free form, etc.

The discontinuous foraminous portions lie below the level of the imperforate portions of the backing means. This results in a three-dimensional effect in all the fiber groupings accumulated above the foraminous portions of the backing means. To put it another way, the continuous raised imperforate portions of the backing means rise above the foraminous portions by at least about or or 4;" or even more if desired. With higher raised imperforate portions, heavier starting webs are used.

During use of the method, the apertured forming means and the backing means are spaced from each other to provide a fiber rearranging zone in which fiber movement in directions parallel to the backing means is permitted in response to applied fluid forces.

Rearranging fluid.The rearranging fluid for use in making the novel fabrics of this invention is preferably water or a similar liquid, but it may be other fluids such as a gas, as described in my Patent No. 2,862,251.

If desired, a vacuum may be applied at the exit side of the fiber rearranging zone to assist in moving the rearranging fluid through the fibrous starting material and in rearranging the fibers of the material into the novel patterned nonwoven fabric of this invention. This feature is most useful when the rearranging fluid is a liquid.

Even though some of the rearranging forces applied to the loose fibrous web in making my fabric are considerably diflerent in magnitude than other forces applied to the loose fibrous web, these rearranging forces of disparate magnitude do not conflict or compete with each other but cooperate with and complement each other to produce uniformity and regularity in the patterns of groups of fiber segments produced. My new nonwoven fabric can be made with patterns which simulate fancy woven and knitted fabrics and which even simulate lace, crocheted fabrics and the like.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully described in conjunctionwith the accompanying drawings wherein:

FIG. '1 is a photomicrograph of a fabric of the present invention at an original enlargement of times.

FIG. 2 is a photomicrograph of another fabric of the present invention at an original enlargement of 5 times.

FIG. 3 is a photomicrograph of a cross-sectional view of the fabric of FIG. 2 at an original enlargement of times.

FIG. 4 is a diagrammatic showing in elevation of one type of apparatus for carrying out the method for producing the fabrics of the present invention.

FIG. 5 is a view in perspective of a portion of a backing means that can be used in the apparatus of FIG. 4.

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 5.

FIG. 7 is an enlarged fragmentary diagrammatic plan view of the foraminous portion of another backing means that can be used with the apparatus of FIG. 4.

FIG. 8 is a cross-sectional view taken along the line 8-8 of FIG. 7.

FIG. 9 is a cross-sectional view taken along the line 9--9 of FIGS. 7 and 8.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION .Referring to the photomicrograph in FIG. 1, there is shown a nonwoven fabric 20 of the present invention. The fabric comprises regular or predetermined discontinuous portions 21, the fiber segments in these discontinuous portions being interentangled in helter-skelter arrangement with these portions protruding out of the plane of thefabric. The discontinuous portions of the fabric are interconnected with each other by a plurality of yarnlike bundles 22 of fiber segments. These yarn-like bundles of fiber segments extend in a continuous pattern throughout the fabrics. The fiber segments in the bundles are closely associated with other fiber segments in the bundle and the fiber segments are generally parallel to the longitudinal axis of the bundle. The yarn-like bundles 22 define holes 23 between them.

With regard to the photomicrograph shown in FIGS. 2 and 3, the fabric 24 has a pattern of discontinuous areas 25, which are generally square in shape and arranged in rows longitudinally and transverse of the fabric. These discontinuous portions comprise fiber segments in helterskelter, interentangled relationship and as shown, in the cross section in FIG. 3, these areas extend out of the general plane of the fabric. These areas have more or less an embossed or impressed wafile design on one surface so that the fiber concentration alternates throughout the areas. The areas have high fiber concentration portions 26 and lower fiber concentration portions 27. The discontinuous areas are interconnected by a plurality of yarn-like bundles 28 of fiber segments. The fiber segments in these bundles are closely associated with other fiber segments in the bundle and aligned generally parallel to the longitudinal axis of the bundle. These yarn-like bundles define areas of low fiber density 29 therebetween and as may be seen in some instances, apertures or holes therebetween.

DESCRIPTION OF MACHINE AND METHOD FOR MAKING FABRICS OF MY INVENTION Referring to FIG. 4 in the drawings, there is shown one form of apparatus for carrying out methods to produce products in accordance with the present invention. Full particulars of this apparatus except for the details of the novel backing or supporting member on which rearrangement of fibers takes place in accordance with the present invention including methods of mounting, rotation, etc., are fully described in U.S. Pat. 2,862,251, issued Dec. 2, 1958 and are incorporated in the present application by reference and thus need not be described in complete detail herein. In view of this reference, the apparatus of FIG. 4 will be described in general terms insofar as its essential elements are the same as in the patent just mentioned, and the novel element of this apparatus, i.e., the backing or supporting member, will be described in more detail.

The apparatus includes a rotatable perforated drum 30 suitably mounted on flanged guide wheels 31 and 32. The drum has apertures 33 uniformly spaced over its entire surface. The guide wheels are mounted for rotation on shafts 34 and 35. Inside the drum there is stationarily mounted along the full width of the drum, a manifold 36 to which a fluid is supplied through conduit 37. On one side of the manifold is a series of nozzles 38 for directing the fluid against the inside surface of the drum.

A novel backing or supporting member 40 is arranged to travel with rotatable drum 30 as will be described below. (The term backing member and support member are used interchangeably throughout this description.)

Support member 40, as shown in FIGS. 5 and 6, has a discontinuous pattern of foraminous portions and a continuous pattern of raised imperforate portions 101 between and interconnecting them. Elements 101a and 101b both of which rise above foraminous portions 100, form a gridwork that extends throughout the area of backing means 40. Elements 101a are wider and lower than elements 101b.

In FIGS. 5 and 6, the foraminous portions are square and are aligned in straight lines longitudinally and transversely over the surface of the member 40. As already indicated above, the foraminous portions of the backing member may have any shape desired. They may also be arranged in any discontinuous pattern over the backing member.

FIG. 6 shows a cross section of the backing means of FIG. 5, from which it is seen that in this embodiment, imperforate portions 101a do not rise as high above foraminous portions 100 as do imperforate portions 101b- The support or backing member 40 passes about drum 30 and separates from the drum at the guide roll 41 which rotates on a shaft 42. The support member. passes downwardly around guide roll 43 rotating on shaft 44 and then rearwardly over a vertically adjustable tensioning and tracking guide roll 45 rotating on ashaft 46 and then around guide roll 47 on a shaft 48. The member passes upwardly and around guide roll 49 rotating on shaft 50 to 'be returned about the periphery of the drum.

The drum and supporting belt provide a rearranging zone between them through which a fibrous starting material may move, to be rearranged under the influence of applied fluid forces into a nonwoven fabric having a plurality of more patterns throughout its area. Tension on the support member is controlled and adjusted by the tensioning and tracking guide roll. The guide rolls are .positioned in slideable brackets which are adjustable to assist in the maintenance of the proper tension of the support member. The tension required will depend upon the weight of the fibrous web being treated and the amount of rearrangement and patterning desired in the final product.

Apertured drum 30 rotates in the direction of the arrow shown, and support member 40 moves in the same direction and at the same peripheral linear speed as the drum, and within the indicated guide channels, so that both longitudinal and lateral translatory motion of the backing means, the apertured forming means, and the fibrous layer with respect to each other are avoided. The fibrous material 60 to be rearranged is fed between the drum and support member at point A, passes through the fiber rearranging zone where fluid rearranging forces are applied to it, and is removed in its new, rearranged form as nonwoven fabric 61 between the support member and apertured drum at point B.

As fibrous material 60 passes through the fiber rearranging zone, a liquid such as water is directed against the inner surfaces of rotating apertured drum 30 through nozzles 38 mounted inside the drum. The liquid passes through drum apertures 33 and through the'fibrous web and thence through the backing means, thereby effecting rearrangement of the fibers of the web.

Vacuum assist box is located against the outside surface of backing means 40. Vacuum box has a slotted surface located closely adjacent the outer surface of belt 40, and through which suction is caused to act upon the web. Suction thus applied assists in the rearrangement of the fibers as the web material passes through the rearranging zone. In addition, it serves to help de-Water the web and prevent flooding during fiber rearrangement. Vacuum box 62 located below drum 30 also helps de-water the web after it is rearranged.

The directions the streams of rearranging fluid projected through the apertures of the apertured drum 30 take as they move into and through the fibrous Web, determine the type of forces applied to the fibers and, in turn, the extent of rearrangement of the fibers. Since the directions the streams of rearranging fluid take after they pass through the apertures are determined by foraminous portions 100 and imperforate portons 101 of support member or backing means 40, it follows that it is the patterns of these areas that at least in part determine the patterns of holes or other areas of low fiber density in the resulting web.

When backing means 40 and apertured forming drum 30 are employed as shown in FIGS. 4, 5, and 6, streams of rearranging fluid passing through forming apertures 33 cause some of the fiber segments that are in registry with continuous imperforate portions 100 of backing means 40 to move into areas of fibrous layer 60overlying foraminous portions 100 of the backing means,-to form mats 'of randomly oriented fiber segments there. At the same time, the streams of rearranging fluid move other fiber segments that are in registry with imperforate portions 101a and 101b into yarn-like bundles of closely associated and substantially parallel fiber segments in positions bridging the continuous imperforate portions of the backing means from one discontinuous foraminous area 100 to another.

This fiber rearrangement produces a first pattern of mats of randomly oriented fiber segments arranged in accordance with the pattern of arrangement of foraminous portions 100 of backing means 40, and a second pattern of yarn-like bundles of fiber segments interconnecting the portions of the fabric in the first pattern. The second pattern corresponds to the configuration of continuous raised imperforate portions 101 of backingmeans 40.

FIG. 7 gives an enlarged fragmentary diagrammatic plan view of the foraminous portions of another backing means that can be used with the apparatus of FIG. 4. Foraminousportion 70 of the backing means shown in FIG. 7 is. formed of coarse woven screen, preferably metal; wires 71 running vertically in that figure are straight, while wires 72 running horizontally weave alternately over and under wires 71. Protuberances 73 are present throughout foraminous portion 70 as the topmost part of each knee of a given strand 72 of the screen that is formed as the strand weaves over and under the strands 71 that lie perpendicular to it.

As a given strand 72 slants downward to pass under a strand 71 perpendicular to it, it crosses two other strands 72 disposed on either side of it, as those strands slant upward to pass over the same perpendicular strand that the given strand will pass under. Each series of such crossing points 74 form a trough, such as trough 75 formed by crossing points 74 in FIGS. 7 and 8, that lies between adjacent protuberances 73. The effective shape of troughs 75, as can be best seen in FIG. 8 (which shows a cross section of element 70 of which a plan view is given in FIG. 7), is substantially an inverted triangle.

A series of slightly deeper troughs 76 is formed between adjacent protuberances 73 but extending at right angles to troughs 75. As best seen in FIG. 9, the bottom of each trough 76 is formed by portions of straight strands 71, with successive protuberances v73 on each side of the trough forming the tops of the trough. As seen in FIG. 9, the effective shape of. troughs 76, may be characterized as a shallow U-shape.

As shown in FIG. 7, a plurality of troughs 75 and a plurality of protuberances 73 alternate in one direction across the surface of foraminous portion 70 of the backing means. FIG. 7 also shows that a plurality of troughs 76 and a plurality of protuberances 73 alternate in a direction perpendicular to troughs 75. Hence a plurality of troughs and a plurality of protuberances alternate in both the longitudinal and transverse directions across the surface of foraminous portion 70 of the backing means.

Use in the method of a backing means having foraminous portions such as element 70 shown in FIGS. 7 through 9, with a starting web that has a Web weight of at least about 800 grains per square yard if made up of fibers of about 1 /2 denier and somewhat heavier for higher denier fibers, produces a nonwoven fabric in which one surface of each of the mats of randomly oriented fiber segments in the fabric is embossed in accordance with a pattern that is complementary to the pattern of protuberances 73 and troughs 75 and 76 on the surface of foraminous portions 70 of the backing means.

During use of this invention, apertured forming means 30 and the backing means of which element 70 is a part are spaced to provide a fiber rearranging zone.

The rearranged web or fabric of the present invention may be treated with an adhesive, dye or other impregnating, printing, or coating material in a conventional manner. For example, to strengthen the rearranged web, any suitable adhesive bonding materials or binders may be included in an aqueous or non-aqueous medium employed as the rearranging fluid. Or an adhesive binder may, if desired, be printed on the rearranged web to provide the necessary fabric strength. Thermoplastic binders may, if desired, be applied to the rearranged Web in powder form before, during or after rearrangement, and then fused to bond the fibers.

The optimum binder content for a given fabric according to this invention depends upon a number of factors, including the nature of the binder material, the size and shape of the binder members and their arrangement in the fabric, the nature and length of the fibers, total fiber weight, and the like. In some instances, because of the strength of the fibers used or the tightness of their interentanglement in the rearrangedweb or fabric, no binder at all need be employed to provide a usable fabric.

Further details and descriptions of methods and apparatus which may be used to produce the novel nonwoven fabrics of the present invention are givenin my commonly assigned patent applications entitled Method and Apparatus for Producing Nonwoven Fabrics Having a plurality of Patterns (Ser. No. 22,309 filed Mar. 24, 1970 and now abandoned) and Method for Producing Nonwoven Fabrics Having a Plurality of Patterns (Ser. -No. 22,304 filed Mar. 24, 1970 and now abandoned). It is to be noted that notall embodiments of the apparatus disclosed in the above-mentioned patent applications will necessarily produce the novel nonwoven fabrics of the present invention.

The following are illustrative examples of use of the method and apparatus of this invention to produce the novel patterned nonwoven fabrics of the present invention:

Example 1 In apparatus as illustrated in FIG. 4, a web 60 of loosely assembled fibers, such as may be obtained by carding, is fed between apertured forming drum 30 and backing means 40. The web weight is about 1200 grains per square yard, and its fiber orientation ratio approximately 7 to 1 in the direction of travel. The web contains viscose rayon fibers approximately 1%," long, of 1 /2 denier.

Apertured forming means 30 has about 165 substantially round holes per square inch, each approximately 0.045" in diameter, or about 30 times the average diameter of the fibers of the fibrous starting material. The holes are arranged in a diamond pattern over the forming means. Each aperture 33 is spaced approximately 0.040" in the diagonal direction from the immediately adjacent aperture on the forming belt.

The discontinuous foraminous portions 100 of backing means 40 are comprised of a woven nylon screen of approximately 28 x 34 mesh or substantially 952 openings per square inch. Each foraminous portion 100 is square in shape, approximately 7 on each side, and is spaced from the immediately adjacent similar foraminous portions by approximately 7 in one direction and about in the other.

Continuous imperforate portions 101a and 101b of backing means 40 comprise a low density polyethylene mesh or grid of the form shown in perspective view in FIG. 5 and in cross section in FIG. 6. The width of each imperforate portion 101a is approximately or about 0.094", which is about two times the diameter of each aperture 33 of apertured forming drum 30. The width of each imperforate portion 101!) is approximately or about equal to the diameter of each forming aperture 33. Together the grid of imperforate portions defines square foraminous portions each of whose sides is approximately i The heights of imperforate portions 101a and 101b are about ,4, and respectively, at their rounded top portions.

With the conditions indicated, good fiber rearrangement and bundling are obtained, and a nonwoven fabric such as shown in the photomicrograph of FIG. 1 which has a plurality of patterns that alternate and extend throughout the fabric, is produced. Nonwoven fabric 20 of FIG. 1 contains a first pattern of fiber segments 21 arranged in accordance with the pattern of arrangement of discontinuous foraminous portions of backing member 40. Fiber segments 21 comprise a mat of randomly oriented segments. During the production of the fabric of FIG. 1, wider imperforate portions 101a extend vertically under the fabric as it is there shown, and narrower imperforate portions 101b run horizontally beneath the fabric as it is there shown.

The nonwoven fabric of this example also contains a second pattern of yarn-like bundles of closely associated and substantially parallel fiber segments 22a and 22b interconnecting portions of the fabric in the first pattern 21. The portion of this second pattern comprised of yarn-like bundles 22a corresponds to the configuration of continuous imperforate portions 101a of backing member 40. Yarn-like bundles 22b are shorter than bundles 22a, because they correspond to narrower imperforate portions 10112 of the backing means. Yarn-like bundles 22a define between them areas of low fiber density 23a and bundles 22b define somewhat smaller areas of low fiber density 23b.

[Example 2 The fibrous starting materialemployed in this example is the same as that used in Example 1. The apparatus is also the same as that of Example 1, except that each foraminous portion of the backing means has more widely spaced protuberances and troughs disposed across its surface. Specifically, foraminous portions 100 of backing means 40 comprise a woven fiber glass screen of approximately 14 X 18 mesh or substantially 252 openings per square inch.

The resulting nonwoven fabric, as seen in (FIG. 2, is a rearranged fabric having a plurality of patterns of fiber segments that alternate and extend throughout the fabric. Nonwoven fabric 24 of FIG. 2 contains a first pattern of fiber segments 25 arranged in accordance with the pattern of arrangement of discontinuous foraminous portions 100 of backing means 40. Fiber segments 25 comprise a mat of randomly oriented segments.

The nonwoven fabric of this example contains a second pattern that includes yarn-like bundles of closely associated and substantially parallel fiber segments 28a 'which interconnect portions of the fabric in the first pattern 25 and define between them areas of low fiber density 29a. The second pattern also includes yarn-like bundles of fiber segments 28b which define between them areas of low fiber density 29b. Yarn-like bundles 29a correspond to the configuration of continuous imperforate portions 101a of backing means 40, and yarn-like bundles 28b correspond to imperforate portions 29b of the backing means.

As seen in FIG. 2, the surface of the fibrous web that is in contact with foraminous portions 100 of backing means 40 is embossed with a pattern that is complementary to the pattern of the protuberances and troughs that alternate across the surface of those portions. This effect is achieved by directing the streams of rearranging fluid against the fibrous web so as to pack down into the troughs and above the protuberances the fiber segments that lie above the foraminous portions of the backing means or are moved there by the rearranging fluid.

(FIG. 3 is a photomicrograph showing a cross-section of the nonwoven fabric of FIG. 2 taken along a line similar to line 3- 3 in the latter figure. The respective groups of fiber segments in the nonwoven fabric of FIG. 3 are indicated by the same designators in that figure as are used for the corresponding parts of the fabric in FIG. 2.

The above detailed description has been given for clearness of understanding only. 'No unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

I claim:

1. A nonwoven fabric with a plurality of patterns of groups of fiber segments that alternate and extend throughout said fabric which comprises: groups of fiber segments in discontinuous portions of the fabric, said discontinuous portions forming a first pattern, the fiber segments in each of said groups being interentan'gled and in helter-skelter arrangement, said groups protruding out of the plane of the fabric, said first discontinuous portions of the fabric being interconnected by a plurality of yarnlike bundles of fiber segments which define areas of low fiberdensity in continuous portions of the fabric that lie between and interconnect said discontinuous portions, said continuous portions forming a second pattern, the fiber segments in each of said bundles being closely associated with other fiber segments in thebundle and lying generally parallel to the longitudinal axis of the bundle.

2. The nonwoven fabric of claim 1 in which said areas of low fiber density are apertures substantially free of fibers.

3. The nonwoven fabric of claim 1 in which each of said groups of fiber segments in said first discontinuous portions of the fabric has alternating areas of different fiber concentration within the group.

4. The nonwoven fabric of claim 1 in which the surface of each of said groups of fiber segments in said first discontinuous portions of the fabricthat lies outside-the plane of the fabrichas alternating high and low areas as one moves across said surface within the group.

5. The nonwoven fabric of claim 1 in which each of said discontinuous portions of the fabric has a substantially square configuration.

6. The nonwoven fabric of claim 5 in which the discontinuous portions of the fabric are disposed in aligned rows extending longitudinally and transversely of the fabric.

7. The nonwoven fabric of claim 6 in which the yarnlike bundles of fiber segments interconnect the discontinuous portions of the fabric in both the longitudinal and transverse directions and the longitudinally connecting yarn-like bundles are of a different size than the transversely connecting yarn-like bundles.

References Cited UNITED STATES PATENTS 3,485,706

ROBERT F. BURNETT, Primary Examiner R. L. MAY, Assistant Examiner US. 01. X.R. 

